EGR Rate Determination Method, Determination Device, Processor, and Vehicle System

Abstract

The present application provides a method and apparatus for determining the EGR rate, a processor, and a vehicle system. The method includes: obtaining inflow information and outflow information, where the inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate in the intake manifold during the current cycle, and the outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate in the intake manifold during the previous cycle, and the intake manifold is a pipe between the outlet of the throttle valve and the inlet of the engine cylinder; determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information; determining the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation; and determining that the EGR rate during the current cycle is the ratio of the exhaust gas pressure to the total gas pressure. The present application solves the problem of inaccurate calculation of the EGR rate in the prior art.

Description

Technical Field

[0001] The present application relates to the field of EGR rate calculation, and more particularly, to a method and device for determining an EGR rate, a computer-readable storage medium, a processor, and a vehicle system. Background Art

[0002] Currently, the calculation formula of the EGR (Exhaust Gas Re-circulation) rate is: EGR rate = exhaust gas mass flow / (fresh air mass flow + exhaust gas mass flow). The mass flow of fresh air is calculated at the throttle position, and the mass flow of EGR exhaust gas is calculated at the EGR valve position. The throttle and the EGR valve are relatively far from the engine cylinder intake valve. Calculating the EGR rate based on the air mass flow at the throttle and the mass flow at the EGR does not represent the true EGR rate entering the engine cylinder. Especially in transient conditions, compared with the volume of the intake pipe and the EGR pipe, the volume of the intake manifold is relatively large. During transient operation, fresh air and EGR exhaust gas will be buffered in the intake manifold and will not immediately enter the cylinder, resulting in inaccurate calculation of the EGR rate. Therefore, there is an urgent need for a solution to solve the problem of inaccurate EGR rate calculation in the prior art. Summary of the Invention

[0003] The main object of the present application is to provide a method and device for determining an EGR rate, a computer-readable storage medium, a processor, and a vehicle system, so as to at least solve the problem of inaccurate EGR rate calculation in the prior art.

[0004] To achieve the above object, according to one aspect of the present application, a method for determining an EGR rate is provided, including: an acquisition step of acquiring inflow information and outflow information, where the inflow information includes the inflow air mass flow and the inflow exhaust gas mass flow of the intake manifold in the current cycle, the outflow information includes the outflow air mass flow and the outflow exhaust gas mass flow of the intake manifold in the previous cycle, and the intake manifold is a pipe between the outlet of the throttle and the inlet of the engine cylinder; a first determination step of determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information; a second determination step of determining the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation; and a third determination step of determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0005] Optionally, based on the inflow information and the outflow information, determining the total mass of air and the total mass of exhaust gas in the intake manifold, includes: integrating the difference between the inflow air mass flow rate and the outflow air mass flow rate to obtain the total mass of air; integrating the difference between the inflow exhaust gas mass flow rate and the outflow exhaust gas mass flow rate to obtain the total mass of exhaust gas.

[0006] Optionally, based on the total mass of air, the total mass of exhaust gas, and the ideal gas state equation, determining the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle, includes: determining the exhaust gas pressure as determining the air pressure in the intake manifold based on the total mass of air and the ideal gas state equation as where, P EGR is the exhaust gas pressure, P Air is the air pressure, M EGR is the total mass of exhaust gas, M Air is the total mass of air, R is the molar gas constant, T is the temperature in the intake manifold, V is the volume of the intake manifold; determining the total gas pressure as the sum of the exhaust gas pressure and the air pressure.

[0007] Optionally, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is a historical predetermined pressure, the exhaust gas pressure in the intake manifold in the previous cycle is a historical exhaust gas pressure, the air pressure in the intake manifold in the previous cycle is a historical air pressure, the total mass flow rate of the gas flowing into the engine cylinder in the previous cycle is a historical total mass flow rate of the gas, and the charging efficiency of the engine cylinder in the previous cycle is a historical charging efficiency. Obtaining the outflow information includes: in the case where the previous cycle is not the initial cycle, determining Mf out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), where, Mf out ′ is the historical total mass flow rate of the gas, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; determining the outflow air mass flow rate as and determining the outflow exhaust gas mass flow rate as In the case where the previous cycle is the initial cycle, receive the pre-stored outflow air mass flow rate and the outflow exhaust gas mass flow rate.

[0008] Optionally, obtain inflow information, including: obtaining the inflow air mass flow rate detected by a first mass flow sensor, the first mass flow sensor being located between the throttle valve and the inlet of the intake manifold; obtaining the inflow exhaust gas mass flow rate detected by a second mass flow sensor, the second mass flow sensor being located between the EGR valve and the inlet of the intake manifold.

[0009] Optionally, after determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure, the method further includes: a fourth determination step of determining that the current cycle is the new previous cycle, and the next cycle of the current cycle is the new current cycle; an execution step of sequentially executing the fourth determination step, the obtaining step, the first determination step, the second determination step, and the third determination step a predetermined number of times to determine multiple EGR rates in real time.

[0010] According to another aspect of the present application, there is provided a device for determining an EGR rate, including: an obtaining unit for performing the obtaining step of obtaining inflow information and outflow information, the inflow information including the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle, the outflow information including the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle, and the intake manifold being a pipe between the outlet of the throttle valve and the inlet of the engine cylinder; a first determination unit for performing the first determination step of determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information; a second determination unit for performing the second determination step of determining the exhaust gas pressure in the intake manifold and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation; and a third determination unit for performing the third determination step of determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0011] According to still another aspect of the present application, there is provided a computer-readable storage medium, the computer-readable storage medium including a stored program, wherein when the program runs, it controls the device where the computer-readable storage medium is located to execute any one of the methods.

[0012] According to yet another aspect of the present application, there is provided a processor for running a program, wherein when the program runs, it executes any one of the methods.

[0013] According to another aspect of the present application, a vehicle system is further provided, including: a vehicle; a controller of the vehicle, the controller includes one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include those for executing any one of the methods.

[0014] Applying the technical solution of the present application, first, obtain the inflow information including the inflow air mass flow rate and the inflow exhaust gas mass flow rate in the intake manifold during the current cycle, and obtain the outflow information including the outflow air mass flow rate and the outflow exhaust gas mass flow rate in the intake manifold during the previous cycle; then, according to the inflow information and the outflow information, determine the total air mass and the total exhaust gas mass in the intake manifold; further, according to the total air mass, the total exhaust gas mass, and the ideal gas state equation, determine the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle; finally, determine that the EGR rate during the current cycle is the ratio of the exhaust gas pressure to the total gas pressure. Compared with the prior art where the EGR rate of the engine cylinder is calculated based on the mass flow rate of fresh air at the throttle position and the mass flow rate of exhaust gas at the EGR valve position, resulting in inaccurate calculation of the EGR rate, the present application utilizes the principle of mass conservation, regards the intake manifold as a closed container with two inputs and one output, calculates the partial pressure ratio of the exhaust gas in the closed container, and uses this partial pressure ratio to represent the EGR rate. Since the intake manifold is relatively close to the engine cylinder and has a relatively large volume, which can play a certain buffering role, using the partial pressure ratio of the exhaust gas in the intake manifold to represent the EGR rate ensures that the calculation position of the EGR rate is closer to the engine cylinder, has higher accuracy and better volatility under transient conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0016] Figure 1 The hardware structure block diagram of a mobile terminal for implementing a method for determining the EGR rate provided in an embodiment of the present application is shown;

[0017] Figure 2 The flowchart of a method for determining the EGR rate provided in an embodiment of the present application is shown;

[0018] Figure 3 The schematic diagram of the connection relationship among the throttle valve, the intake manifold, and the EGR valve provided in an embodiment of the present application is shown;

[0019] Figure 4The flowchart shows another method for determining the EGR rate provided according to an embodiment of the present application;

[0020] Figure 5 The schematic diagram shows a closed-loop EGR calculation provided according to an embodiment of the present application;

[0021] Figure 6 The block diagram shows a device for determining the EGR rate provided according to an embodiment of the present application.

[0022] Among them, the above-mentioned drawings include the following reference numerals:

[0023] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 300. Throttle valve; 301. EGR valve; 302. Intake manifold; 303. Engine cylinder. Detailed implementation manners

[0024] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0026] It should be noted that the terms "first", "second", etc. in the specification, claims and drawings of the present application are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0027] For the convenience of description, some nouns or terms related to the embodiments of the present application are explained below:

[0028] EGR: Exhaust Gas Recirculation, which introduces the exhaust gas on the exhaust side of the engine to the intake side and enters the cylinder together with fresh air, can reduce the combustion temperature and suppress knocking.

[0029] EGR rate: The ratio of the amount of recirculated exhaust gas to the total intake air volume inhaled into the cylinder.

[0030] As introduced in the background art, there is a problem of inaccurate EGR rate calculation in the prior art. To solve the above problem, embodiments of the present application provide a method for determining the EGR rate, a determining device, a computer-readable storage medium, a processor, and a vehicle system.

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0032] The method embodiments provided in the embodiments of the present application can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking the operation on a mobile terminal as an example, Figure 1 is a hardware structure block diagram of a mobile terminal for a method of determining the EGR rate according to an embodiment of the present invention. As Figure 1 shown, the mobile terminal may include one or more ( Figure 1 only one is shown in Figure 1 a processor 102 (the processor 102 may include, but is not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data. Among them, the mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those of ordinary skill in the art can understand that Figure 1 the structure shown in Figure 1 is only schematic and does not limit the structure of the mobile terminal. For example, the mobile terminal may further include more or fewer components than those shown in

[0033] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the display method of device information in the embodiments of the present invention. The processor 102 executes various functional applications and data processing by running the computer programs stored in the memory 104, that is, implements the described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memories. In some instances, the memory 104 may further include a memory remotely disposed relative to the processor 102, and these remote memories can be connected to the mobile terminal through a network. Examples of the network include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the network may include the wireless network provided by the communication provider of the mobile terminal. In one instance, the transmission device 106 includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices through a base station and thus can communicate with the Internet. In one instance, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0034] In this embodiment, a method for determining the EGR rate running on a mobile terminal, a computer terminal, or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0035] Figure 2 It is a flowchart of the method for determining the EGR rate according to the embodiments of the present application. As Figure 2 shown, the method includes the following steps:

[0036] Step S201, an acquisition step, acquires inflow information and outflow information. The inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle, and the outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle. The intake manifold is the pipe between the outlet of the throttle valve and the inlet of the engine cylinder;

[0037] Specifically, the vehicle's controller obtains the inflow information and the outflow information step by step with a predetermined time length as the step size to calculate the EGR rate. The previous cycle is the previous cycle of the current cycle, and each cycle is a step size. The inflow air mass flow rate of the intake manifold refers to the mass flow rate of fresh air entering the intake manifold through the throttle valve. In this application, the intake manifold is regarded as a closed container with two inputs and one output. Fresh air control and exhaust gas enter the intake manifold through two inputs respectively for mixing, and the mixed gas flows out of the intake manifold through one output and enters the engine cylinder.

[0038] In one embodiment, the current cycle and the previous cycle can be taken to be as small as only including one moment, obtaining the current moment and the previous moment. Determining the EGR rate within the current cycle is to determine the EGR rate at an instantaneous moment.

[0039] As Figure 3 shown, the throttle valve 300 is a controllable valve for controlling the fresh air entering the engine. The vehicle also includes an EGR valve 301, and the EGR valve is a valve for controlling the amount of exhaust gas entering the intake manifold 302. The fresh air enters the intake manifold 302 after passing through the throttle valve 300 and is mixed with the exhaust gas entering the intake manifold 302 through the EGR valve 301, obtaining buffering and will not immediately flow out of the intake manifold 302 and enter the engine cylinder 303. The inflow information is the gas mass flow rate of the fresh air and the exhaust gas currently entering the intake manifold. Since the time length of the step size is small, the mixed gas will not immediately flow out of the intake manifold. Therefore, the outflow information selects the gas mass flow rate of the fresh air and the exhaust gas flowing out of the intake manifold in the previous cycle of the current cycle.

[0040] Step S202, the first determination step, determines the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information;

[0041] Specifically, the first determination step calculates the total air mass and the total exhaust gas mass according to the inflow air mass flow rate, the inflow exhaust gas mass flow rate, the outflow air mass flow rate, and the outflow exhaust gas mass flow rate of the intake manifold. The specific calculation method can be any suitable method. For example, according to the inflow air mass flow rate, the outflow air mass flow rate, the known air density, the inner diameter of the intake manifold, and the formula of the four: mass flow rate = air density × π × inner diameter / 4 × air flow velocity × 3600, calculate the air flow velocity, and then calculate the total air mass according to the air flow velocity and the cross-sectional area inside the intake manifold. The calculation method of the total exhaust gas mass is the same. It is also possible to perform time integration of the inflow air mass flow rate and the outflow air mass flow rate for the duration of the current cycle to obtain the total air mass. The calculation method of the total exhaust gas mass is the same.

[0042] Step S203, the second determination step, according to the total air mass, the total exhaust gas mass, and the ideal gas state equation, determine the exhaust gas pressure in the intake manifold and the total gas pressure in the intake manifold during the current cycle;

[0043] Specifically, the ideal gas state equation is PV = mRT′, where P is the gas pressure, R is the molar gas constant, T′ is the temperature, and m is the gas mass. According to the total air mass, the total exhaust gas mass, and this ideal gas state equation, the exhaust gas pressure and the total gas pressure in the intake manifold can be obtained. Among them, the total gas pressure is the sum of the exhaust gas pressure and the air pressure in the intake manifold.

[0044] Step S204, the third determination step, according to the exhaust gas pressure and the total gas pressure, determine that the EGR rate during the current cycle is the ratio of the exhaust gas pressure to the total gas pressure.

[0045] Specifically, this application uses the partial pressure ratio of the EGR exhaust gas at the intake manifold to represent the gas volume ratio of the current EGR exhaust gas in the engine cylinder, that is, the EGR rate of the current cycle. Since the intake manifold is relatively close to the engine cylinder, the calculation position of the EGR rate in this application is relatively close to the engine cylinder, making the calculation of the EGR rate under transient conditions more accurate.

[0046] Through the above embodiments, first obtain the inflow information including the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold during the current cycle, and obtain the outflow information including the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold during the previous cycle; then, according to the inflow information and the outflow information, determine the total air mass and the total exhaust gas mass in the intake manifold; then, according to the total air mass, the total exhaust gas mass, and the ideal gas state equation, determine the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle; finally, determine that the EGR rate during the current cycle is the ratio of the exhaust gas pressure to the total gas pressure. Compared with the prior art, in which the EGR rate of the engine cylinder is calculated based on the mass flow rate of fresh air at the throttle position and the mass flow rate of exhaust gas at the EGR valve position, resulting in inaccurate calculation of the EGR rate, this application uses the principle of mass conservation, regards the intake manifold as a closed container with two inputs and one output, calculates the partial pressure ratio of the exhaust gas in this closed container, and uses this partial pressure ratio to represent the EGR rate. Since the position of the intake manifold is relatively close to the engine cylinder and the volume of the intake manifold is relatively large, which can play a certain buffering role, using the partial pressure ratio of the exhaust gas in the intake manifold to represent the EGR rate ensures that the calculation position of the EGR rate is closer to the engine cylinder, has higher accuracy and better volatility under transient conditions.

[0047] In an alternative solution, the specific implementation manner of the step S202 may be asFigure 4 As shown in the figure, it specifically includes the following steps:

[0048] Step S2021: Integrate the difference between the inflowing air mass flow rate and the outflowing air mass flow rate to obtain the total air mass.

[0049] Step S2022: Integrate the difference between the inflowing exhaust gas mass flow rate and the outflowing exhaust gas mass flow rate to obtain the total exhaust gas mass.

[0050] In the embodiment, by using the principle of mass conservation, the intake manifold is regarded as a closed container with two inputs and one output. Integrate the difference between the inflowing air mass flow rate into the intake manifold and the outflowing air mass flow rate from the intake manifold, and integrate the difference between the inflowing exhaust gas mass flow rate into the intake manifold and the outflowing exhaust gas mass flow rate from the intake manifold, respectively obtaining the total air mass and the total exhaust gas mass at the intake manifold, ensuring that the air quality and exhaust gas quality at the intake manifold can be obtained more accurately, providing relatively accurate data support for calculating the proportion of the partial pressure of the exhaust gas pressure at the intake manifold based on the air quality and exhaust gas quality subsequently.

[0051] Specifically, integrating the difference between the inflowing air mass flow rate and the outflowing air mass flow rate is to integrate the difference obtained by subtracting the outflowing air mass flow rate from the inflowing air mass flow rate within the current cycle to obtain the total air mass at the intake manifold. Integrating the difference between the inflowing exhaust gas mass flow rate and the outflowing exhaust gas mass flow rate is to integrate the difference obtained by subtracting the outflowing exhaust gas mass flow rate from the inflowing exhaust gas mass flow rate within the current cycle to obtain the total exhaust gas mass at the intake manifold.

[0052] To further ensure obtaining the exhaust gas pressure and the total gas pressure in the intake manifold simply and accurately, according to some exemplary embodiments of the present application, based on the total air mass, the total exhaust gas mass, and the ideal gas state equation, determine the exhaust gas pressure and the total gas pressure in the intake manifold within the current cycle, including: determining the exhaust gas pressure as Determining the air pressure in the intake manifold as where P EGR is the exhaust gas pressure, P Air is the air pressure, M EGR is the total exhaust gas mass, M Air is the total air mass, R is the molar gas constant, T is the temperature in the intake manifold, V is the volume of the intake manifold; determining the total gas pressure as the sum of the exhaust gas pressure and the air pressure.

[0053] Specifically, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is the historical predetermined pressure, the pressure of the exhaust gas in the intake manifold in the previous cycle is the historical exhaust gas pressure, the pressure of the air in the intake manifold in the previous cycle is the historical air pressure, the total mass flow rate of the gas flowing into the engine cylinder in the previous cycle is the historical gas total mass flow rate, and the charging efficiency of the engine cylinder in the previous cycle is the historical charging efficiency. Obtaining the outflow information includes: when the previous cycle is not the initial cycle, determining the historical gas total mass flow rate as Mf out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), where Mf out ′ is the historical gas total mass flow rate, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; determining the outflow air mass flow rate as and determining the outflow exhaust gas mass flow rate as When the previous cycle is the initial cycle, receiving the pre-stored outflow air mass flow rate and outflow exhaust gas mass flow rate. Since at the same engine speed, the total mass flow rate of the mixture gas flowing into the engine cylinder is proportional to the difference between the total gas pressure at the intake manifold and the EGR exhaust gas pressure remaining in the cylinder. In this embodiment, according to the charging efficiency corresponding to the previous cycle, the pressure of the residual exhaust gas in the engine cylinder, the exhaust gas pressure and air pressure in the intake manifold, the total gas mass flow rate corresponding to the previous cycle is determined. Then, according to this gas total mass flow rate, the exhaust gas pressure ratio and the air pressure ratio, the outflow air mass flow rate and outflow exhaust gas mass flow rate are determined, realizing a relatively accurate and convenient determination of the outflow air mass flow rate and outflow exhaust gas mass flow rate of the intake manifold, providing accurate outflow information for calculating the EGR rate of the current cycle, and further ensuring that the EGR rate can be calculated more accurately.

[0054] Among them, the initial cycle is the first cycle calculated by using the method of the present application. When the previous cycle is the initial cycle, there is no previous cycle for the initial cycle. Therefore, the outflow information is the artificially pre-stored outflow air mass flow rate and outflow exhaust gas mass flow rate. In addition, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke is related to the engine speed, valve overlap angle, and the ratio of the exhaust manifold pressure to the intake manifold pressure, and can be obtained through bench calibration. The charging efficiency is related to the engine speed and can also be obtained through bench calibration.

[0055] It should be noted that when calculating the EGR rate of the next cycle of the current cycle, the outflow air mass flow rate and outflow exhaust gas mass flow rate of the intake manifold in the current cycle are required, and their calculation methods are the same as those of the outflow air mass flow rate and outflow exhaust gas mass flow rate of the intake manifold in the previous cycle.

[0056] Furthermore, obtaining the inflow information includes: obtaining the inflow air mass flow rate detected by the first mass flow sensor, where the first mass flow sensor is located between the throttle valve and the inlet of the intake manifold; obtaining the inflow exhaust gas mass flow rate detected by the second mass flow sensor, where the second mass flow sensor is located between the EGR valve and the inlet of the intake manifold. By obtaining the detection data of the first mass flow sensor located between the throttle valve and the inlet of the intake manifold as the air mass flow rate at the inlet of the intake manifold, and obtaining the detection data of the second mass flow sensor located between the EGR valve and the inlet of the intake manifold as the exhaust gas mass flow rate at the inlet of the intake manifold, the inflow air mass flow rate and the inflow exhaust gas mass flow rate at each moment can be obtained relatively simply and in real time.

[0057] Of course, the method of obtaining the inflow information is not limited to the above method, and those skilled in the art can also use any other suitable method to obtain the inflow information. For example, obtaining the air pressure detected by the first pressure sensor located between the throttle valve and the inlet of the intake manifold as the first pressure, and obtaining the exhaust gas pressure detected by the second pressure sensor located between the EGR valve and the inlet of the intake manifold as the second pressure; according to the corresponding relationship between the pressure and flow rate of the gas and the first pressure, determining the flow rate of the air at the inlet of the intake manifold as the first flow rate, and according to the first flow rate and the volume of the intake manifold, determining the inflow air mass flow rate; according to the corresponding relationship and the second pressure, determining the flow rate of the exhaust gas at the inlet of the intake manifold as the second flow rate, and according to the second flow rate and the volume of the intake manifold, determining the inflow exhaust gas mass flow rate.

[0058] Other methods can also be used to obtain the inflow information. For another example, the air pressure detected by a first pressure sensor located between the throttle valve and the inlet of the intake manifold is obtained as the first pressure, and the exhaust gas pressure detected by a second pressure sensor located between the EGR valve and the inlet of the intake manifold is obtained as the second pressure; according to the first pressure and the ideal gas state equation, the inflow air mass flow rate is determined; according to the second pressure and the ideal gas state equation, the inflow exhaust gas mass flow rate is determined.

[0059] In yet another alternative solution, after determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure, the method further includes: a fourth determination step of determining the current cycle as the new previous cycle and the next cycle of the current cycle as the new current cycle; an execution step of sequentially executing the fourth determination step, the acquisition step, the first determination step, the second determination step, and the third determination step a predetermined number of times to determine multiple EGR rates in real time. Through the above loop process, a closed-loop calculation of the EGR rate is achieved. While further ensuring the calculation accuracy of the EGR rate under transient conditions, the influence of data fluctuations on the EGR rate is fully considered, further ensuring that the EGR rate obtained in real time is relatively stable, which facilitates the subsequent control of the opening of the EGR valve according to the EGR rate determined in real time.

[0060] Specifically, the predetermined number of times is a value preset by a person, such as 5 times, 10 times, etc., and those skilled in the art can flexibly set the predetermined number of times according to the actual situation. In addition to limiting the number of loops, the execution step can also limit the loop duration. For example, the execution step is used to sequentially execute the fourth determination step, the acquisition step, the first determination step, the second determination step, and the third determination step until the execution duration reaches the preset duration to determine multiple EGR rates in real time.

[0061] Further, after the step S204, the method further includes: determining an opening value of the EGR valve according to the EGR rate in the current cycle; controlling the EGR valve to open to the opening value.

[0062] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the method for determining the EGR rate of the present application will be described in detail below with reference to specific embodiments.

[0063] This embodiment relates to a specific method for determining the EGR rate, as Figure 5 shown, including the following steps:

[0064] Step S1: Calculate the total mass M of the EGR exhaust gas at the intake manifold EGR = ∫MfEGRin -Mf EGRout , and calculate the total air mass M of fresh air at the intake manifold Air = ∫Mf Airin -Mf Airout , where Mf EGRin is the mass flow rate of the inflowing exhaust gas at the intake manifold at the current moment, and Mf EGRout is the mass flow rate of the outflowing exhaust gas at the intake manifold at the previous moment of the current moment (i.e., Figure 5 the mass flow rate of the exhaust gas flowing into the engine cylinder), and Mf Airin is the mass flow rate of the inflowing air at the intake manifold at the current moment, and Mf Airout is the mass flow rate of the outflowing air at the intake manifold at the previous moment (i.e., Figure 5 the mass flow rate of the air flowing into the engine cylinder), and then perform step S2;

[0065] Step S2: According to the ideal gas state equation PV = mRT′, the exhaust gas pressures of the fresh air and the EGR exhaust gas at the intake manifold can be obtained respectively as follows:

[0066]

[0067] Calculate the at the current moment, and then perform step S3;

[0068] Step S3: At the same engine speed, the total gas mass flow rate of the mixture gas flowing into the cylinder is proportional to the difference between the total gas pressure in the intake manifold and a predetermined pressure, and this predetermined pressure is the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke, that is:

[0069] Mf out = f(n)×(P 总 -P 内部EGR )

[0070] P 总 = P EGR +P Air

[0071] where Mf out is the total gas mass flow rate at the current moment, f(n) is the charging efficiency at the current moment, P 内部EGR is the predetermined pressure, P EGR is the exhaust gas pressure at the current moment, and P Air is the air pressure at the current moment;

[0072] The mass flow rates of the fresh air and the EGR exhaust gas flowing into the engine cylinder are respectively:

[0073]

[0074]

[0075] After that, step S2 is executed;

[0076] Step S4: Return to step S1 to continue calculating the EGR rate at the next moment.

[0077] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0078] The embodiment of the present application also provides a device for determining the EGR rate. It should be noted that the device for determining the EGR rate in the embodiment of the present application can be used to execute the method for determining the EGR rate provided by the embodiment of the present application. The device is used to implement the above-mentioned embodiment and the preferred implementation manners, and those that have been described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0079] The following introduces the device for determining the EGR rate provided by the embodiment of the present application.

[0080] Figure 6 It is a schematic diagram of the device for determining the EGR rate according to the embodiment of the present application. As Figure 6 shown, the device includes:

[0081] An acquisition unit 10, configured to acquire steps, acquire inflow information and outflow information, where the inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle, and the outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle. The intake manifold is a pipeline between the outlet of the throttle valve and the inlet of the engine cylinder;

[0082] Specifically, the vehicle controller calculates the EGR rate by acquiring the inflow information and the outflow information step by step with a predetermined time length as the step size. The previous cycle is the previous cycle of the current cycle, and each cycle is a step size. The inflow air mass flow rate of the intake manifold refers to the mass flow rate of fresh air entering the intake manifold through the throttle valve. In the present application, the intake manifold is regarded as a closed container with two inputs and one output. Fresh air control and exhaust gas enter the intake manifold through two inputs respectively for mixing, and the mixed gas flows out of the intake manifold through one output and enters the engine cylinder.

[0083] In one embodiment, the current cycle and the previous cycle can be as small as including only one moment, obtaining the current moment and the previous moment. Determining the EGR rate within the current cycle is to determine the EGR rate at an instantaneous moment.

[0084] As Figure 3 shown, the throttle valve 300 is a controllable valve for controlling the fresh air entering the engine. The vehicle further includes an EGR valve 301, and the EGR valve is a valve for controlling the amount of exhaust gas entering the intake manifold 302. The fresh air enters the intake manifold 302 after passing through the throttle valve 300 and is mixed with the exhaust gas entering the intake manifold 302 through the EGR valve 301, obtaining buffering and will not immediately flow out of the intake manifold 302 into the engine cylinder 303. The inflow information is the gas mass flow rate of the fresh air and the exhaust gas currently entering the intake manifold. Since the duration of the step size is small, the mixed gas will not immediately flow out of the intake manifold. Therefore, the outflow information selects the gas mass flow rate of the fresh air and the exhaust gas flowing out of the intake manifold in the previous cycle of the current cycle.

[0085] The first determination unit 20 is used for the first determination step. According to the inflow information and the outflow information, determine the total mass of air and the total mass of exhaust gas in the intake manifold;

[0086] Specifically, the first determination step calculates the total mass of air and the total mass of exhaust gas according to the inflow air mass flow rate, the inflow exhaust gas mass flow rate, the outflow air mass flow rate, and the outflow exhaust gas mass flow rate. The specific calculation method can be any suitable method. For example, according to the inflow air mass flow rate, the outflow air mass flow rate, the known air density, the inner diameter of the intake manifold, and the formula of the four: mass flow rate = air density × π × inner diameter / 4 × air flow velocity × 3600, calculate the air flow velocity, and then according to the air flow velocity and the cross-sectional area inside the intake manifold, calculate the total mass of air. The calculation method of the total mass of exhaust gas is the same. It is also possible to perform time integration of the inflow air mass flow rate and the outflow air mass flow rate in the current cycle to obtain the total mass of air. The calculation method of the total mass of exhaust gas is the same.

[0087] The second determination unit 30 is used for the second determination step. According to the total mass of air, the total mass of exhaust gas, and the ideal gas state equation, determine the exhaust gas pressure in the intake manifold and the total gas pressure in the intake manifold within the current cycle;

[0088] Specifically, the ideal gas state equation is PV = mRT', where P is the gas pressure, R is the molar gas constant, T' is the temperature, and m is the gas mass. Based on the total air mass, the total exhaust gas mass, and this ideal gas state equation, the exhaust gas pressure and the total gas pressure in the intake manifold can be obtained. Among them, the total gas pressure is the sum of the exhaust gas pressure and the air pressure in the intake manifold.

[0089] A third determination unit 40 is configured for a third determination step to determine that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure based on the exhaust gas pressure and the total gas pressure.

[0090] Specifically, the present application uses the partial pressure ratio of the EGR exhaust gas at the intake manifold to represent the ratio of the gas amount of the current EGR exhaust gas in the engine cylinder, that is, the EGR rate of the current cycle. Since the intake manifold is relatively close to the engine cylinder, the calculation position of the EGR rate in the present application is relatively close to the engine cylinder, making the calculation of the EGR rate under transient conditions more accurate.

[0091] Through the above embodiments, the acquisition unit acquires the inflow information including the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle, and acquires the outflow information including the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle; the first determination unit determines the total air mass and the total exhaust gas mass in the intake manifold based on the inflow information and the outflow information; the second determination unit determines the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle based on the total air mass, the total exhaust gas mass, and the ideal gas state equation; the third determination unit determines that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure. Compared with the prior art in which the EGR rate of the engine cylinder is calculated based on the mass flow rate of fresh air at the throttle position and the mass flow rate of exhaust gas at the EGR valve position, resulting in inaccurate calculation of the EGR rate, the present application utilizes the principle of mass conservation, regards the intake manifold as a closed container with two inputs and one output, calculates the partial pressure ratio of the exhaust gas in the closed container, and uses this partial pressure ratio to represent the EGR rate. Since the position of the intake manifold is relatively close to the engine cylinder and the volume of the intake manifold is relatively large, which can play a certain buffering role, using the partial pressure ratio of the exhaust gas in the intake manifold to represent the EGR rate ensures that the calculation position of the EGR rate is closer to the engine cylinder, has higher accuracy and better volatility under transient conditions.

[0092] In an alternative solution, the first determination unit specifically includes:

[0093] A first integration module is configured to integrate the difference between the inflow air mass flow rate and the outflow air mass flow rate to obtain the total air mass;

[0094] A second integration module for integrating the difference between the mass flow rate of the inflowing exhaust gas and the mass flow rate of the outflowing exhaust gas to obtain the total mass of the exhaust gas.

[0095] In the embodiment, by using the principle of mass conservation, the intake manifold is regarded as a closed container with two inputs and one output, and the difference between the mass flow rate of the air flowing into the intake manifold and the mass flow rate of the air flowing out of the intake manifold is integrated, and the difference between the mass flow rate of the exhaust gas flowing into the intake manifold and the mass flow rate of the exhaust gas flowing out of the intake manifold is integrated, respectively obtaining the total mass of the air and the total mass of the exhaust gas at the intake manifold, ensuring that the air quality and exhaust gas quality at the intake manifold can be obtained more accurately, and providing more accurate data support for calculating the proportion of the partial pressure of the exhaust gas pressure at the intake manifold according to the air quality and exhaust gas quality.

[0096] Specifically, integrating the difference between the mass flow rate of the inflowing air and the mass flow rate of the outflowing air is to integrate the difference obtained by subtracting the mass flow rate of the outflowing air from the mass flow rate of the inflowing air within the current period to obtain the total mass of the air at the intake manifold. Integrating the difference between the mass flow rate of the inflowing exhaust gas and the mass flow rate of the outflowing exhaust gas is to integrate the difference obtained by subtracting the mass flow rate of the outflowing exhaust gas from the mass flow rate of the inflowing exhaust gas within the current period to obtain the total mass of the exhaust gas at the intake manifold.

[0097] To further ensure obtaining the exhaust gas pressure and the total gas pressure in the intake manifold simply and accurately, according to some exemplary embodiments of the present application, the second determination unit includes: a first determination module for determining the exhaust gas pressure as a second determination module for determining the air pressure in the intake manifold as where P EGR is the exhaust gas pressure, P Air is the air pressure, M EGR is the total mass of the exhaust gas, M Air is the total mass of the air, R is the molar gas constant, T is the temperature in the intake manifold, V is the volume of the intake manifold; a third determination module for determining the total gas pressure as the sum of the exhaust gas pressure and the air pressure.

[0098] Specifically, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is the historical predetermined pressure, the pressure of the exhaust gas in the intake manifold in the previous cycle is the historical exhaust gas pressure, the pressure of the air in the intake manifold in the previous cycle is the historical air pressure, the total mass flow rate of the gas flowing into the engine cylinder in the previous cycle is the historical gas total mass flow rate, and the charging efficiency of the engine cylinder in the previous cycle is the historical charging efficiency. The obtaining unit includes: a fourth determination module, configured to, when the previous cycle is not the initial cycle, determine the historical gas total mass flow rate as Mf out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), where Mf out ′ is the historical gas total mass flow rate, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; a fifth determination module, configured to determine the outflow air mass flow rate as and determine the outflow exhaust gas mass flow rate as A receiving module, configured to, when the previous cycle is the initial cycle, receive the pre-stored outflow air mass flow rate and the outflow exhaust gas mass flow rate. Since at the same engine speed, the total mass flow rate of the mixture gas flowing into the engine cylinder is proportional to the difference between the total gas pressure at the intake manifold and the EGR exhaust gas pressure remaining in the cylinder. In this embodiment, according to the charging efficiency, the pressure of the residual exhaust gas in the engine cylinder, the exhaust gas pressure and the air pressure in the intake manifold corresponding to the previous cycle, the total mass flow rate of the gas corresponding to the previous cycle is determined. Then, according to the total mass flow rate of the gas, the proportion of the exhaust gas pressure and the proportion of the air pressure, the outflow air mass flow rate and the outflow exhaust gas mass flow rate are determined, realizing relatively accurate and convenient determination of the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold, providing accurate outflow information for calculating the EGR rate of the current cycle, and further ensuring that the EGR rate can be calculated relatively accurately.

[0099] Wherein, the initial cycle is the first cycle calculated by using the device of the present application. When the previous cycle is the initial cycle, there is no previous cycle for the initial cycle. Therefore, the outflow information is the artificially pre-stored outflow air mass flow rate and outflow exhaust gas mass flow rate. In addition, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke is related to the engine speed, the valve overlap angle, and the ratio of the exhaust manifold pressure to the intake manifold pressure, and can be obtained through bench calibration. The charging efficiency is related to the engine speed and can also be obtained through bench calibration.

[0100] It should be noted that when calculating the EGR rate of the next cycle of the current cycle, the outflow air mass flow rate and outflow exhaust gas mass flow rate of the intake manifold in the current cycle are required, and their calculation methods are the same as those of the outflow air mass flow rate and outflow exhaust gas mass flow rate of the intake manifold in the previous cycle.

[0101] Further, the obtaining unit includes: a first obtaining module, configured to obtain the inflow air mass flow rate detected by a first mass flow sensor, where the first mass flow sensor is located between the throttle valve and the inlet of the intake manifold; a second obtaining module, configured to obtain the inflow exhaust gas mass flow rate detected by a second mass flow sensor, where the second mass flow sensor is located between the EGR valve and the inlet of the intake manifold. By obtaining the detection data of the first mass flow sensor located between the throttle valve and the inlet of the intake manifold as the air mass flow rate at the inlet of the intake manifold, and obtaining the detection data of the second mass flow sensor located between the EGR valve and the inlet of the intake manifold as the exhaust gas mass flow rate at the inlet of the intake manifold, the inflow air mass flow rate and the inflow exhaust gas mass flow rate at each moment can be obtained relatively simply and in real time.

[0102] Of course, the method for obtaining the inflow information is not limited to the above method, and those skilled in the art can also use any other suitable method to obtain the inflow information. For example, obtaining the air pressure detected by a first pressure sensor located between the throttle valve and the inlet of the intake manifold as the first pressure, and obtaining the exhaust gas pressure detected by a second pressure sensor located between the EGR valve and the inlet of the intake manifold as the second pressure; determining the air flow velocity at the inlet of the intake manifold as the first flow velocity according to the corresponding relationship between the gas pressure and the flow velocity and the first pressure, and determining the inflow air mass flow rate according to the first flow velocity and the volume of the intake manifold; determining the exhaust gas flow velocity at the inlet of the intake manifold as the second flow velocity according to the corresponding relationship and the second pressure, and determining the inflow exhaust gas mass flow rate according to the second flow velocity and the volume of the intake manifold.

[0103] Other methods can also be used to obtain the inflow information. For another example, obtain the air pressure detected by the first pressure sensor located between the throttle valve and the inlet of the intake manifold as the first pressure, and obtain the exhaust gas pressure detected by the second pressure sensor located between the EGR valve and the inlet of the intake manifold as the second pressure; determine the inflow air mass flow rate according to the first pressure and the ideal gas state equation; determine the inflow exhaust gas mass flow rate according to the second pressure and the ideal gas state equation.

[0104] In another alternative solution, the device further includes: a fourth determination unit, configured to, after determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure, perform a fourth determination step to determine the current cycle as the new previous cycle, and the next cycle of the current cycle as the new current cycle; an execution unit, configured to execute steps, and sequentially execute the fourth determination step, the acquisition step, the first determination step, the second determination step, and the third determination step a predetermined number of times to determine multiple EGR rates in real time. Through the above cyclic process, a closed-loop calculation of the EGR rate is achieved. While further ensuring the calculation accuracy of the EGR rate under transient conditions, the influence of data fluctuations on the EGR rate is fully considered, further ensuring that the EGR rate obtained in real time is relatively stable, which facilitates the subsequent control of the opening degree of the EGR valve according to the EGR rate determined in real time.

[0105] Specifically, the predetermined number of times is a value preset by a person, such as 5 times, 10 times, etc. Those skilled in the art can flexibly set the predetermined number of times according to the actual situation. In addition to limiting the number of cycles, the execution step can also limit the cycle duration. For example, the execution step is used to sequentially execute the fourth determination step, the acquisition step, the first determination step, the second determination step, and the third determination step until the execution duration reaches the preset duration to determine multiple EGR rates in real time.

[0106] Further, the device further includes: a fifth determination unit, configured to determine the opening degree value of the EGR valve according to the EGR rate in the current cycle after the third determination step; a control unit, configured to control the EGR valve to open to the opening degree value.

[0107] The EGR rate determination device includes a processor and a memory. The acquisition unit, the first determination unit, the second determination unit, the third determination unit, etc. are all stored in the memory as program units, and the processor executes the program units stored in the memory to implement corresponding functions. The modules are all located in the same processor; or, the respective modules are located in different processors in any combination form.

[0108] The processor contains a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and by adjusting the kernel parameters, at least the problem of inaccurate EGR rate calculation in the prior art can be solved.

[0109] The memory may include non-permanent memory in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0110] An embodiment of the present invention provides a computer-readable storage medium, which includes a stored program. When the program runs, it controls the device where the computer-readable storage medium is located to execute the method for determining the EGR rate.

[0111] Specifically, the method for determining the EGR rate includes:

[0112] Step S201, an acquisition step, to acquire the inflow information and the outflow information. The inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle. The outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle. The intake manifold is the pipeline between the outlet of the throttle valve and the inlet of the engine cylinder.

[0113] Specifically, the vehicle controller takes a predetermined time length as a step, and acquires the inflow information and the outflow information step by step to calculate the EGR rate. The previous cycle is the previous cycle of the current cycle, and each cycle is a step. The inflow air mass flow rate of the intake manifold refers to the mass flow rate of the fresh air entering the intake manifold through the throttle valve. In this application, the intake manifold is regarded as a closed container with two inputs and one output. Fresh air control and exhaust gas enter the intake manifold through two inputs respectively for mixing, and the mixed gas flows out of the intake manifold through one output and enters the engine cylinder.

[0114] Step S202, a first determination step, to determine the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information.

[0115] Specifically, in the first determination step, the total air mass and the total exhaust gas mass are calculated based on the inflowing air mass flow rate, the inflowing exhaust gas mass flow rate, the outflowing air mass flow rate, and the outflowing exhaust gas mass flow rate of the intake manifold. The specific calculation method can be any suitable method. For example, according to the inflowing air mass flow rate, the outflowing air mass flow rate, the known air density, the inner diameter of the intake manifold, and the formula of the four: mass flow rate = air density × π × inner diameter / 4 × air velocity × 3600, the air velocity is calculated, and then based on the air velocity and the cross-sectional area inside the intake manifold, the total air mass is calculated. The calculation method of the total exhaust gas mass is the same. It is also possible to perform a time integration of the inflowing air mass flow rate and the outflowing air mass flow rate for the current cycle to obtain the total air mass. The calculation method of the total exhaust gas mass is the same.

[0116] Step S203, the second determination step, determines the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation.

[0117] Specifically, the ideal gas state equation is PV = mRT′, where P is the gas pressure, R is the molar gas constant, T′ is the temperature, and m is the gas mass. According to the total air mass, the total exhaust gas mass, and this ideal gas state equation, the exhaust gas pressure and the total gas pressure in the intake manifold can be obtained. Among them, the total gas pressure is the sum of the exhaust gas pressure and the air pressure in the intake manifold.

[0118] Step S204, the third determination step, determines that the EGR rate during the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0119] Specifically, the present application uses the partial pressure ratio of the EGR exhaust gas at the intake manifold to represent the gas volume ratio of the current EGR exhaust gas in the engine cylinder, that is, the EGR rate of the current cycle. Since the intake manifold is relatively close to the engine cylinder, the calculation position of the EGR rate in the present application is relatively close to the engine cylinder, making the calculation of the EGR rate under transient conditions more accurate.

[0120] Optionally, determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflowing information and the outflowing information includes: integrating the difference between the inflowing air mass flow rate and the outflowing air mass flow rate to obtain the total air mass; integrating the difference between the inflowing exhaust gas mass flow rate and the outflowing exhaust gas mass flow rate to obtain the total exhaust gas mass.

[0121] Optionally, according to the total air mass, the total exhaust gas mass, and the ideal gas state equation, determining the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle includes: determining the exhaust gas pressure as determining the air pressure in the intake manifold according to the total air mass and the ideal gas state equation as wherein, P EGR is the exhaust gas pressure, P Air is the air pressure, M EGR is the total exhaust gas mass, M Air is the total air mass, R is the molar gas constant, T is the temperature in the intake manifold, and V is the volume of the intake manifold; determining the total gas pressure as the sum of the exhaust gas pressure and the air pressure.

[0122] Optionally, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is a historical predetermined pressure, the exhaust gas pressure in the intake manifold in the previous cycle is a historical exhaust gas pressure, the air pressure in the intake manifold in the previous cycle is a historical air pressure, the total mass flow rate of the gas flowing into the engine cylinder in the previous cycle is a historical total gas mass flow rate, and the charging efficiency of the engine cylinder in the previous cycle is a historical charging efficiency. Obtaining the outflow information includes: in the case that the previous cycle is not the initial cycle, according to the historical charging efficiency, the historical predetermined pressure, the historical exhaust gas pressure, and the historical air pressure, determining Mf out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), wherein, Mf out ′ is the historical total gas mass flow rate, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; determining the outflow air mass flow rate as and determining the outflow exhaust gas mass flow rate as In the case that the previous cycle is the initial cycle, receiving the pre-stored outflow air mass flow rate and the outflow exhaust gas mass flow rate.

[0123] Optionally, obtain the inflow information, including: obtaining the inflow air mass flow rate detected by a first mass flow sensor, where the first mass flow sensor is located between the throttle valve and the inlet of the intake manifold; obtaining the inflow exhaust gas mass flow rate detected by a second mass flow sensor, where the second mass flow sensor is located between the EGR valve and the inlet of the intake manifold.

[0124] Optionally, after determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure, the method further includes: a fourth determination step of determining that the current cycle is the new previous cycle, and the next cycle of the current cycle is the new current cycle; an execution step of sequentially executing the fourth determination step, the obtaining step, the first determination step, the second determination step, and the third determination step a predetermined number of times to determine multiple EGR rates in real time.

[0125] An embodiment of the present invention provides a processor for running a program, where the program, when running, executes the method for determining the EGR rate.

[0126] Specifically, the method for determining the EGR rate includes:

[0127] Step S201, an obtaining step of obtaining inflow information and outflow information, where the inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle, the outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle, and the intake manifold is a pipeline between the outlet of the throttle valve and the inlet of the engine cylinder;

[0128] Step S202, a first determination step of determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information;

[0129] Step S203, a second determination step of determining the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation;

[0130] Step S204, a third determination step of determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0131] An embodiment of the present invention provides a vehicle system, including: a vehicle; a controller of the vehicle, the controller including one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and when the one or more programs are executed, at least the following steps are implemented:

[0132] Step S201, an acquisition step, to acquire inflow information and outflow information, where the inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate in the intake manifold during the current cycle, and the outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate in the intake manifold during the previous cycle, and the intake manifold is a pipe between the outlet of the throttle valve and the inlet of the engine cylinder;

[0133] Step S202, a first determination step, to determine the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information;

[0134] Step S203, a second determination step, to determine the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation;

[0135] Step S204, a third determination step, to determine that the EGR rate during the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0136] The device in this article can be a server, a PC, a PAD, a mobile phone, etc.

[0137] Optionally, determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information includes: integrating the difference between the inflow air mass flow rate and the outflow air mass flow rate to obtain the total air mass; integrating the difference between the inflow exhaust gas mass flow rate and the outflow exhaust gas mass flow rate to obtain the total exhaust gas mass.

[0138] Optionally, determining the exhaust gas pressure and the total gas pressure in the intake manifold during the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation includes: determining the exhaust gas pressure as Determining the air pressure in the intake manifold according to the total air mass and the ideal gas state equation as where P EGR is the exhaust gas pressure, P Air is the air pressure, M EGRis the total mass of the exhaust gas, M Air is the total mass of the air, R is the molar gas constant, T is the temperature in the intake manifold, and V is the volume of the intake manifold; determine that the total gas pressure is the sum of the exhaust gas pressure and the air pressure.

[0139] Optionally, the pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is a historical predetermined pressure, the exhaust gas pressure in the intake manifold in the previous cycle is a historical exhaust gas pressure, the air pressure in the intake manifold in the previous cycle is a historical air pressure, the total mass flow rate of the gas flowing into the engine cylinder in the previous cycle is a historical total gas mass flow rate, and the charging efficiency of the engine cylinder in the previous cycle is a historical charging efficiency. Obtain the outflow information, including: in the case where the previous cycle is not the initial cycle, determine Mf according to the historical charging efficiency, the historical predetermined pressure, the historical exhaust gas pressure, and the historical air pressure out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), where Mf out ′ is the historical total gas mass flow rate, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; determine that the outflow air mass flow rate is and determine that the outflow exhaust gas mass flow rate is In the case where the previous cycle is the initial cycle, receive the pre-stored outflow air mass flow rate and the outflow exhaust gas mass flow rate.

[0140] Optionally, obtain the inflow information, including: obtain the inflow air mass flow rate detected by the first mass flow sensor, where the first mass flow sensor is located between the throttle valve and the inlet of the intake manifold; obtain the inflow exhaust gas mass flow rate detected by the second mass flow sensor, where the second mass flow sensor is located between the EGR valve and the inlet of the intake manifold.

[0141] Optionally, after determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure, the method further includes: a fourth determination step of determining that the current cycle is the new previous cycle, and the next cycle of the current cycle is the new current cycle; an execution step of sequentially executing the fourth determination step, the obtaining step, the first determination step, the second determination step, and the third determination step a predetermined number of times to determine multiple EGR rates in real time.

[0142] An embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, at least the following steps are implemented:

[0143] Step S201, an acquisition step, to acquire inflow information and outflow information. The inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle. The outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle. The intake manifold is a pipe between the outlet of the throttle valve and the inlet of the engine cylinder;

[0144] Step S202, a first determination step, to determine the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information;

[0145] Step S203, a second determination step, to determine the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation;

[0146] Step S204, a third determination step, to determine that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0147] The device herein may be a server, a PC, a PAD, a mobile phone, etc.

[0148] The present application also provides a computer program product, which is suitable for executing a program initialized with at least the following method steps when executed on a data processing device:

[0149] Step S201, an acquisition step, to acquire inflow information and outflow information. The inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle. The outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle. The intake manifold is a pipe between the outlet of the throttle valve and the inlet of the engine cylinder;

[0150] Step S202, a first determination step, to determine the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information;

[0151] Step S203, a second determination step, to determine the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation;

[0152] Step S204, the third determination step, determine that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure.

[0153] Obviously, those skilled in the art should understand that each module or step of the present invention can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. They can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. In this way, the present invention is not limited to any specific combination of hardware and software.

[0154] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0155] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one or more flows or multiple flows and / or blocks Figure 1 one or more blocks or multiple blocks.

[0156] These computer program instructions can also be stored in a computer-readable memory capable of guiding the computer or other programmable data processing devices to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device implements the functions specified in Figure 1 one or more flows or multiple flows and / or blocks Figure 1 one or more blocks or multiple blocks.

[0157] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, causing a series of operational steps to be performed on the computer or other programmable apparatus to generate a computer-implemented process, so that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one process Figure 1 one process or a plurality of processes and / or blocks Figure 1 steps of a block or a plurality of blocks.

[0158] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0159] The memory may include non-permanent memory in the computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

[0160] Computer-readable media includes both permanent and non-permanent, removable and non-removable media implemented by any method or technology for storing information. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0161] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of another identical element in the process, method, commodity or device comprising the element.

[0162] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for determining the EGR rate, characterized in that Including: An obtaining step of obtaining inflow information and outflow information, where the inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle, the outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle, and the intake manifold is a pipe between the outlet of the throttle valve and the inlet of the engine cylinder; A first determination step of determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information; A second determination step of determining the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation; A third determination step of determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure; The first determination step includes: Integrating the difference between the inflow air mass flow rate and the outflow air mass flow rate to obtain the total air mass; Integrating the difference between the inflow exhaust gas mass flow rate and the outflow exhaust gas mass flow rate to obtain the total exhaust gas mass; The pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is a historical predetermined pressure, the exhaust gas pressure in the intake manifold in the previous cycle is a historical exhaust gas pressure, the air pressure in the intake manifold in the previous cycle is a historical air pressure, the total gas mass flow rate flowing into the engine cylinder in the previous cycle is a historical total gas mass flow rate, and the charging efficiency of the engine cylinder in the previous cycle is a historical charging efficiency. Obtaining the outflow information includes: When the previous cycle is not the initial cycle, determine the historical total gas mass flow rate as Mf according to the historical charging efficiency, the historical predetermined pressure, the historical exhaust gas pressure, and the historical air pressure out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), where Mf out ′ is the historical total gas mass flow rate, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; Determine that the mass flow rate of the outlet air quality is and determine that the mass flow rate of the outlet exhaust gas is In the case where the previous cycle is the initial cycle, receiving the pre-stored outflow air mass flow rate and the outflow exhaust gas mass flow rate.

2. The method according to claim 1, wherein Determining the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation includes: Determining the exhaust gas pressure as according to the total exhaust gas mass and the ideal gas state equation; Based on the total air mass and the ideal gas state equation, determine that the air pressure in the intake manifold is where P EGR is the exhaust gas pressure, P Air is the air pressure, M EGR is the total exhaust gas mass, M Air is the total air mass, R is the molar gas constant, T is the temperature in the intake manifold, and V is the volume of the intake manifold; Determining the total gas pressure as the sum of the exhaust gas pressure and the air pressure.

3. The method according to claim 1 or 2, characterized in that, Obtaining the inflow information includes: Obtaining the inflow air mass flow rate detected by a first mass flow sensor, where the first mass flow sensor is located between the throttle valve and the inlet of the intake manifold; Obtaining the inflow exhaust gas mass flow rate detected by a second mass flow sensor, where the second mass flow sensor is located between the EGR valve and the inlet of the intake manifold.

4. The method according to claim 1 or 2, characterized in that After determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure, the method further includes: A fourth determination step of determining that the current cycle is the new previous cycle, and the next cycle of the current cycle is the new current cycle; An execution step of sequentially executing the fourth determination step, the obtaining step, the first determination step, the second determination step, and the third determination step a predetermined number of times to determine multiple EGR rates in real time.

5. An EGR rate determination device, characterized in that, Including: An acquisition unit, configured to perform an acquisition step of acquiring inflow information and outflow information. The inflow information includes the inflow air mass flow rate and the inflow exhaust gas mass flow rate of the intake manifold in the current cycle. The outflow information includes the outflow air mass flow rate and the outflow exhaust gas mass flow rate of the intake manifold in the previous cycle. The intake manifold is a pipe between the outlet of the throttle valve and the inlet of the engine cylinder. A first determination unit, configured to perform a first determination step of determining the total air mass and the total exhaust gas mass in the intake manifold according to the inflow information and the outflow information. A second determination unit, configured to perform a second determination step of determining the exhaust gas pressure and the total gas pressure in the intake manifold in the current cycle according to the total air mass, the total exhaust gas mass, and the ideal gas state equation. A third determination unit, configured to perform a third determination step of determining that the EGR rate in the current cycle is the ratio of the exhaust gas pressure to the total gas pressure according to the exhaust gas pressure and the total gas pressure. The first determination unit includes: A first integration module, configured to integrate the difference between the inflow air mass flow rate and the outflow air mass flow rate to obtain the total air mass. A second integration module, configured to integrate the difference between the inflow exhaust gas mass flow rate and the outflow exhaust gas mass flow rate to obtain the total exhaust gas mass. The pressure of the residual exhaust gas in the engine cylinder after the exhaust stroke in the previous cycle is a historical predetermined pressure. The exhaust gas pressure in the intake manifold in the previous cycle is a historical exhaust gas pressure. The air pressure in the intake manifold in the previous cycle is a historical air pressure. The total gas mass flow rate flowing into the engine cylinder in the previous cycle is a historical total gas mass flow rate. The charging efficiency of the engine cylinder in the previous cycle is a historical charging efficiency. The acquisition unit includes: A fourth determination module, configured to determine, when the previous cycle is not the initial cycle, the total historical gas mass flow rate as Mf according to the historical charging efficiency, the historical predetermined pressure, the historical exhaust gas pressure, and the historical air pressure out ′ = f(n)′ × (P EGR ′ + P Air ′ - P 内部EGR ′), where Mf out ′ is the total historical gas mass flow rate, f(n)′ is the historical charging efficiency, P 内部EGR ′ is the historical predetermined pressure, P EGR ' is the historical exhaust gas pressure, P Air ' is the historical air pressure; A fifth determination module, configured to determine that the mass flow rate of the outflowing air quality is and to determine that the mass flow rate of the outflowing exhaust gas is A receiving module, configured to receive the pre-stored outflow air mass flow rate and the outflow exhaust gas mass flow rate when the previous cycle is the initial cycle.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein when the program runs, it controls the device where the computer-readable storage medium is located to execute the method according to any one of claims 1 to 4.

7. A processor, characterized in that, The processor is configured to run a program, wherein when the program runs, it executes the method according to any one of claims 1 to 4.

8. A vehicle system, characterized in that, Comprising: A vehicle; A controller of the vehicle. The controller includes one or more processors, a memory, and one or more programs. The one or more programs are stored in the memory and are configured to be executed by the one or more processors. The one or more programs include a method for executing any one of claims 1 to 4.

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